Question

When a ray of light is refracted from one medium to another, then the wavelength changes from 6000Å to 4000Å. The critical angle for the interface will be ______.

Options

• `sin^-1(2/3)`

• `sin^-1(2/sqrt3)`

• `cos^-1(2/3)`

• `cos^-1(2/sqrt3)`

Answer 1

When a ray of light is refracted from one medium to another, then the wavelength changes from 6000Å to 4000Å. The critical angle for the interface will be `underline(sin^-1(2/3))`.

Explanation:

`mu="v"_1/"v"_2=("v"lambda_1)/("v"lambda_2)=6000/4000=3/2`

`theta=sin^-1(2/3)`